We use original equipment, dedicated to the purpose, developed and produced by RadioAstroLab (with the support of FASAR Elettronica), to monitor the environment in all weather conditions, day and night. Special (patented) microwave radiometers receive the natural electromagnetic radiation of bodies (such as the ground, water and the atmosphere) emitted by the effect of the temperature and the energetic interactions between the atoms and the molecules that constitute them and analyze in real time the data to obtain important information on the observed scenario.
The functioning of the system can be understood by remembering that a ground is all the more reflective, if observed in the microwave band of the electromagnetic spectrum, the greater the quantity and extension of free water present in a thin surface layer. The reflectivity of the soil, very low when it is dry and bare, tends to increase in the presence of vegetation, moisture and, above all, free water. A microwave radiometer estimates this parameter indirectly, measuring the brightness temeprature of the scenario, a magnitude mainly dependent on the presence of water, secondarily on other variables such as temperature, soil composition, its surface roughness, the presence of vegetation and the radiation of the atmosphere reflected from the surface towards the instrument. Appropriate calibration procedures minimize the effects of secondary parameters on the measurement.
Furthermore, when you observe a moving surface such as a flow of water, with waves and ripples, the reflectivity of the scenario varies continuously: the microwave radiation coming from the atmosphere and the environment, reflected from the surface towards the instrument, diffuses in all directions with varying intensity (scattering) causing important fluctuations in the measurement, which depend on the speed and turbulence of the water. These properties are used to monitor the dynamics of a surface of water flowing in a river basin.